<!DOCTYPE html>
<html>
<head>
    <title>WKT</title>
    <link rel="stylesheet" href="https://openlayers.org/en/v5.3.0/css/ol.css" type="text/css">
    <!-- The line below is only needed for old environments like Internet Explorer and Android 4.x -->
    <script src="https://cdn.polyfill.io/v2/polyfill.min.js?features=requestAnimationFrame,Element.prototype.classList,URL"></script>
    <script src="./js/ol-debug.js"></script>

</head>
<body>
<div id="map" class="map"></div>
<script>
    // import Map from 'ol/Map.js';
    // import View from 'ol/View.js';
    // import WKT from 'ol/format/WKT.js';
    // import {Tile as TileLayer, Vector as VectorLayer} from 'ol/layer.js';
    // import {OSM, Vector as VectorSource} from 'ol/source.js';

    // var raster = new ol.layer.TileLayer({
    var raster = new ol.layer.Tile({
        source: new ol.source.OSM()
    });

    var wkt = 'POLYGON((10.689 -25.092, 34.595 ' +
        '-20.170, 38.814 -35.639, 13.502 ' +
        '-39.155, 10.689 -25.092))';

    var format = new ol.format.WKT();

    var feature = format.readFeature(wkt, {
        dataProjection: 'EPSG:4326',
        featureProjection: 'EPSG:3857'
    });

    // var vector = new ol.layer.VectorLayer({
    var vector = new ol.layer.Vector({
        // source: new VectorSource({
        source: new ol.source.Vector({
            features: [feature]
        })
    });

    var map = new ol.Map({
        layers: [raster, vector],
        target: 'map',
        view: new ol.View({
            center: [2952104.0199, -3277504.823],
            zoom: 4
        })
    });
</script>
</body>
</html>